摘要
考虑二次电子的产生和散射,利用MonteCarlo方法模拟了具有高斯分布特征的低能入射电子束斑在抗蚀剂中的散射过程,分别得到了电子束在抗蚀剂中的穿透深度和能量沉积的分布图。发现在能量小于2 5keV范围内的模拟结果与实验结果相吻合,这比用传统的不考虑二次电子的Bethe公式得到的模拟结果更加符合实际的电子散射过程,精度更高。另外还发现电子束能量越低,曝光的分辨率和效率越高,这一结果也与实验相吻合。结果表明,二次电子的产生和散射对电子束曝光起了重要的作用,需考虑它们的影响。
The complex scattering process of the low-energy electron beams with the Gaussian distribution in the PMMA is simulated by a Monte Carlo method. Considering the influences of the secondary electrons and corresponding scattering process, the penetration depth of electrons and energy deposition distribution in the resist are presented under different exposure conditions.It is found that the simulation results with electron energy less than 2.5 keV are in good agreement with the experimental ones, and more accurate compared with that of the conventional Monte Carlo approaches in the CSDA (continous slow down approximation) model. It is also found that the lower the electron beam energy is, the higher the resolution and the efficiency are, which is also in good agreement with the corresponding experimental ones. The present results show that the secondary electron and corresponding scattering process play an important role in the electron beam exposure, it is reasonable to consider their influences in the simulations.
出处
《微细加工技术》
2004年第4期1-6,共6页
Microfabrication Technology
基金
国家自然科学基金重大研究计划资助项目(90307003)
山东省自然科学基金资助项目(Y2003G03)
山东省科技攻关计划基金资助项目(022090105)
